In some diseases, it is desirable to modify the blood pressure in an artery leading to a particular organ in the body. This may be done, for example, to achieve constriction or reduction of soft organs in acute or chronic indications. It may also be done to relieve arterial pressure to an organ such as the brain following or in anticipation of blood vessel rupture. Currently such arterial occlusion is achieved by engaging a mechanical clamp over the artery wall and manually tightening the clamp until some partial occlusion is achieved.
Quite obviously, the major drawback of this type of occlusion system is that it does not control blood pressure, but simply causes a constant reduction in flow area at the point in the artery where the clamp is installed. Accordingly, if for some reason, the incoming blood pressure increases, there is a commensurate increase in the outgoing pressure leading to the body site which increase may be unacceptably high and dangerous to the patient. Likewise if there is a reduction in the incoming pressure to the artery, there may be an unacceptable further reduction in the outgoing pressure. Such unwanted and unexpected increases or decreases in the blood pressure to the body site served by that artery could cause serious and permanent injury to the patient.
One way to avoid the above problem is to continuously monitor the blood pressure to the body site of interest and manually open or close the clamp to offset observed decreases or increases in blood pressure. However, this necessitates having a nurse constantly in attendance at the patient's bedside and even then the reaction time may not be fast enough to assure reliable control. It would, therefore, be desirable to be able to control arterial pressure automatically.